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my 741 case 8 3/4 gear swap

mopower440

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This is my first ring and pinion swap. Finally, after probably 6 or 7 tries, i got the pinion preload to 20. Put it all together and here is the pattern..Thoughts on what to do next..Im assuming the pinion needs to go deeper a little..?

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The pattern looks acceptable. I would try adding 2 to 3 thou and rechecking the pattern.
What is your backlash at ?
 
Agreed, pinion looks a tad bit too shallow. Also need to check the reverse side of the ring pattern too. Compare coast and drive patterns.
 
The pattern looks acceptable. I would try adding 2 to 3 thou and rechecking the pattern.
What is your backlash at ?
Backlash is a hair too much, 10. I may re-set the backlash back to between 6-8 and check it again. Now, if i add 2-3 thousandths to deepen the pinion, will i have to remove that much from the preload shims also so the preload stays good?
 
I have a setup tool where the pattern never looked right to me and after testing several after they were plugged into a car, they were quiet and for many miles stayed quiet, I trusted the setup tool but that doesn't look bad....
 
I have a setup tool where the pattern never looked right to me and after testing several after they were plugged into a car, they were quiet and for many miles stayed quiet, I trusted the setup tool but that doesn't look bad....
There is definitely an “art” to setting a diff. You can follow directions exactly, but many times it really comes down to experience and feel.
 
There is definitely an “art” to setting a diff. You can follow directions exactly, but many times it really comes down to experience and feel.
Yup...after doing several and running them, I decided to trust the setup tool and quit paying attention to what the pattern looked like.
 
I have a setup tool where the pattern never looked right to me and after testing several after they were plugged into a car, they were quiet and for many miles stayed quiet, I trusted the setup tool but that doesn't look bad....
you saying mine doesnt look bad?
 
Are you using new gears? I believe your current pattern is acceptable. If you have used gears-it's a crap shoot.
Mike
 
Are you using new gears? I believe your current pattern is acceptable. If you have used gears-it's a crap shoot.
Mike
yes, they are new gears and bearings. I wanted a different gear ratio.
 
Tighten the backlash up and recheck your pattern before you change the pinion shim. The backlash setting has an affect on the pattern reading.
Adding shim to change the pinion depth won't affect the preload setting.
I like to set the backlash toward the tighter side the backlash spec's. The backlash will open up a little after driving.
 
you saying mine doesnt look bad?
I'm saying mine never looked right lol. Did you get any paper work with the new gears on what patterns are acceptable?
 
I'm saying mine never looked right lol. Did you get any paper work with the new gears on what patterns are acceptable?
Oh crap..i wa hoping you were saying mine didnt look bad
 
Oh crap..i wa hoping you were saying mine didnt look bad
Looks to me like the pinion could be a little deeper....and again, did paperwork showing acceptable patterns come with the gears?
 
Looks to me like the pinion could be a little deeper....and again, did paperwork showing acceptable patterns come with the gears?
yes it did come with the paper, but i just wanted you guys opinion also as i may not see something yall see. I also thought that the pinion needs to go a hair deeper. As a guess, how much more shim would you start with?
 
yes it did come with the paper, but i just wanted you guys opinion also as i may not see something yall see. I also thought that the pinion needs to go a hair deeper. As a guess, how much more shim would you start with?
.005"
 
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